/Engine/Source/Runtime/WebBrowser/Public/IWebBrowserCookieManager.h
This function expects each attribute to be well-formed. It will check for disallowed characters (e.g. the ';' character is disallowed within the cookie Value field) and fail without setting the cookie if such characters are found.
void SetCookie ( const [FString](API\Runtime\Core\Containers\FString) & URL, const [FCookie](API\Runtime\WebBrowser\IWebBrowserCookieManager\FCookie) & Cookie, [TFunction](API\Runtime\Core\GenericPlatform\TFunction)< void(bool)> Completed )